It has been known in the related art to provide a scattering layer in an organic LED element in order to improve light extraction efficiency of an organic LED element (for example, see Patent Document 1).
The scattering layer described in Patent Document 1, is formed by dispersing a scattering material in a base material. Glass that does not contain alkali metal is exemplified as the base material.
Optical glass containing P2O5, Bi2O3 and ZnO and having a high refractive index, a low-temperature softening property, and a low thermal expansion rate has been known (for example, see Patent Document 2).